Steinhaus ME, Salzmann SN, Lovecchio F, Shifflett GD, Yang J, Kueper J, Sama AA, Girardi FP, Cammisa FP, Hughes AP.

SPINE, vol. 44, no. 3, pp. 177–184, Feb. 2019

Summary by Elie Kozaily MD

At the 2018 ICM, the recommendation was made to take intraoperative samples from every revision joint arthroplasty case in order to screen for potential infection [1–3]. In contrast, guidelines for intraoperative specimen collection during spine revision surgeries remain undefined, largely due to a paucity of research. In their retrospective study, Steinhaus et al. addressed two questions (1) what are the patient and surgery related factors that lead surgeons to send intraoperative cultures in a presumed aseptic revision spine surgery? (2) What are the risk factors for a positive intraoperative culture?

The study reviewed 595 consecutive spine revision surgeries between 2008 and 2013. Seventeen cases with a pre-operative diagnosis of infection were excluded. Cultures were obtained for 112 of the remaining 578 cases (19.4%). Of note, the decision to obtain cultures was based on the judgement of the surgeon, knowing that pre-operative work up had not suggested infection. Factors associated with significantly increased odds of having intraoperative cultures were obesity (OR=2.4), history of instrumentation (OR=2.4), thoracolumbar surgery (OR=5.2), preoperative diagnosis of implant failure (OR=9.0) or pseudarthrosis (OR=8.0). Conversely, time between index and revision surgery (OR=0.9) and surgery on cervical spine (OR=0.2) significantly decreased the odds of obtaining cultures. Positive cultures were identified in 45/112 cases (40.1%). Staphylococcus was the most common species (55.6%), Propionibacterium acnes (48.9%) was the single most common organism, and 22.2% of cultures were polymicrobial. Male sex (OR=3.4) and revision diagnosis of pseudarthrosis (OR=4.1) were both strongly associated with a positive culture while fusion procedures (OR=0.30) were negatively associated with a positive culture. Based on their results, the authors recommended cultures in revision cases for pseudarthrosis even with a negative preoperative work-up.

Limitations of the study include selection bias of samples cultured and lack of data from the cases in which cultures were not obtained. Furthermore, it was not known what intraoperative findings led to the decision to obtain intraoperative samples.

References

1. D. E. Padgett, A. Silverman, F. Sachjowicz, R. B. Simpson, A. G. Rosenberg, and J. O. Galante, “Efficacy of intraoperative cultures obtained during revision total hip arthroplasty,” J. Arthroplasty, vol. 10, no. 4, pp. 420–426, Aug. 1995, doi: 10.1016/S0883-5403(05)80140-8.
2. B. L. Atkins et al., “Prospective Evaluation of Criteria for Microbiological Diagnosis of Prosthetic-Joint Infection at Revision Arthroplasty,” J. Clin. Microbiol., vol. 36, no. 10, pp. 2932–2939, 1998, doi: 10.1128/JCM.36.10.2932-2939.1998.
3. A. M. E. Jacobs, M. Bénard, J. F. Meis, G. van Hellemondt, and J. H. M. Goosen, “The unsuspected prosthetic joint infection : incidence and consequences of positive intra-operative cultures in presumed aseptic knee and hip revisions,” Bone Jt. J., vol. 99-B, no. 11, pp. 1482–1489, Nov. 2017, doi: 10.1302/0301-620X.99B11.BJJ-2016-0655.R2.